Curable composition and shaped product

ABSTRACT

A curable composition comprises a cationic curable silicone resin and a leveling agent, the cationic curable silicone resin comprises a silsesquioxane unit, has a monomer unit having an epoxy group in a proportion of not less than 50% by mol in a total monomer unit, and has a number average molecular weight of 1000 to 3000.

TECHNICAL FIELD

The present invention relates to a curable composition (a hardcoatliquid or a hardcoat agent) useful for a hardcoat film having desiredabrasion resistance, transparency, or other properties or a hardcoatsheet as a glass substitute. The present invention also relates to ashaped product obtainable by curing the composition.

BACKGROUND ART

Glass is known as a material having a very large surface hardness. Forexample, a glass having a surface pencil hardness increased to 9H by analkali ion exchange treatment is also known. Unfortunately, the alkaliion exchange treatment of glass, which produces alkali waste fluids inlarge quantities, has a large burden on the environment. Further, theglass is fragile due to a large specific gravity and a low flexibilitythereof. Thus since the glass fails to be produced or processed by aroll-to-roll system and is necessarily produced or processed in the formof a sheet, the production efficiency is low.

A plastic material, such as a polyester, has an excellent flexibility,although the plastic material has a small surface hardness. Thus theplastic material is easily scratched and has a low abrasion resistance.In order to protect the plastic material from scratches, a curable resin(such as a photo-curable resin) is applied on a surface of a plasticsubstrate and cured to form a hardcoat layer having a large hardness.The applications of the hardcoat film having a hardcoat layer are nowexpanding. According to the purposes, the hardcoat film may be requiredto have a surface hardness or a heat resistance equivalent to a glass.

Japanese Patent Application Laid-Open Publication No. 2005-262597(JP-2005-262597A, Patent Document 1) discloses a hardcoat film that isexcellent in abrasion resistance and sliding property and is used for apen input side of a pen input transparent touch panel. The hardcoat filmhas a substrate film and a coat layer on at least one side of thesubstrate film; the coat layer consists of a resin compositioncontaining 0.1 to 10 parts by weight of an ultraviolet-curable siliconeresin having a molecular weight of 500 to 20000 relative to 100 parts byweight of an ultraviolet-curable acrylate resin. In this document, asthe ultraviolet-curable silicone resin, a radical-polymerization typeresin and a cationic polymerization type resin are described; as thecationic polymerization type resin, a polydimethylsiloxane having anepoxypropoxypropyl end and an(epoxycyclohexylethyl)methylsiloxane-dimethylsiloxane copolymer areexemplified. This document also discloses that the ultraviolet-curablesilicone resin preferably has a molecular weight of 500 to 20000 inorder to express a pen-sliding property. In Examples of this document,the hardcoat layer formed has a pencil hardness of 3H.

Japanese Patent Application Laid-Open Publication No. 2009-279840(JP-2009-279840A, Patent Document 2) discloses a laminate containing afirst cured resin layer having a pencil hardness of not higher than HBand a thickness of 10 to 200 μm and a second cured resin layer having apencil hardness of not lower than H and a thickness of 2 to 50 μm,wherein the first cured resin layer is obtained by curing a firstradiation-curable resin composition, and the second cured resin layer isobtained by curing a second radiation-curable resin composition. Thisdocument discloses a radical-polymerizable monomer and aradical-polymerizable oligomer as a radiation-curable resin. In Examplesof this document, the second cured resin layer formed has a pencilhardness of 4H.

Unfortunately, these cured resin layers have insufficient abrasionresistance. Generally, a hardcoat layer obtained by radicalpolymerization of a polyfunctional acrylic monomer has a pencil hardnessof about 3H, although a higher hardness is required depending onapplications. In order to increase the hardness of the hardcoat layer,it is possible to make the crosslinking density higher by increasing thenumber of functional groups in the curable resin or to increase thethickness of the hardcoat layer. Unfortunately, the resulting hardcoatlayer curls or cracks due to contraction generated by hardening.Moreover, although there is also a method for increasing the hardness ofthe hardcoat layer by addition of an inorganic fine particle, it isdifficult to prepare a layer having specific properties according toapplications. For example, it is difficult to select a material for ahardcoat layer to be used in an optical application that requires a hightransparency. For optical and other applications, it is also known thata fluorine-containing leveling agent is added in order to improve thesurface smoothness or the antifouling property. Unfortunately, theaddition of the fluorine-containing material tends to decrease theabrasion resistance.

RELATED ART DOCUMENTS Patent Documents

Patent Document 1: JP-2005-262597A (claim 1, paragraphs [0016], [0023],and [0024], and Examples)

Patent Document 2: JP-2009-279840A (claim 1, paragraph [0018], Examples)

SUMMARY OF INVENTION Technical Problem

It is therefore an object of the present invention to provide a curablecomposition (a hardcoat liquid or a hardcoat agent) for obtaining acured product having improved surface hardness and abrasion resistance,and a shaped product obtainable by curing the composition.

Another object of the present invention is to provide a curablecomposition for obtaining a cured product having an excellent surfacesmoothness, a high transparency, and an improved external appearance,and a shaped product obtainable by curing the composition.

It is still another object of the present invention to provide a curablecomposition of which even a thick cured product can be prevented fromcurling or cracking and can be produced efficiently, and a shapedproduct obtainable by curing the composition.

It is a further object of the present invention to provide a curablecomposition for obtaining a cured product having improved heatresistance, antifouling property, and sliding property, and a shapedproduct obtainable by curing the composition.

Solution to Problem

The inventors of the present invention made intensive studies to achievethe above objects and finally found that the combination use of aspecific cationic curable silicone resin and a leveling agent improvessurface hardness and abrasion resistance of a cured product thereof. Thepresent invention was accomplished based on the above findings.

That is, an aspect of the present invention provides a curablecomposition (or a coating composition) comprising a cationic curablesilicone resin and a leveling agent. The cationic curable silicone resincomprises a silsesquioxane unit, has a monomer unit having an epoxygroup in a proportion of not less than 50% by mol in a total monomerunit, and has a number average molecular weight of 1000 to 3000. Thecationic curable silicone resin may have a silsesquioxane unitrepresented by the formula (1): R¹SiO_(3/2) (wherein R¹ represents agroup containing an epoxy group; a hydrogen atom; or a hydrocarbongroup) in a proportion of not less than 50% by mol in the total monomerunit constituting the cationic curable silicone resin. The cationiccurable resin may further comprise a unit represented by the formula(2): R¹SiO(OR²) (wherein R¹ represents a group containing an epoxygroup; a hydrogen atom; or a hydrocarbon group; R² represents a hydrogenatom or a C₁₋₄alkyl group), and may have a molar ratio of thesilsesquioxane unit relative to the unit represented by the formula (2)of not less than 5. The silsesquioxane unit may comprise a unitrepresented by the formula (3): R³SiO_(3/2) (wherein R³ represents agroup containing an alicyclic epoxy group) and a unit represented by theformula (4): R⁴SiO_(3/2) (wherein R⁴ represents an aryl group which mayhave a substituent). The cationic curable silicone resin may have amolecular weight distribution Mw/Mn of about 1 to 3. The leveling agentmay comprise a silicone-series leveling agent and/or afluorine-containing leveling agent and have at least one of a reactivegroup to an epoxy group, and a hydrolytically condensable group. Theleveling agent may have a proportion of about 0.1 to 10 parts by weightrelative to 100 parts by weight of the cationic curable silicone resin.The leveling agent may comprise a silicone-series leveling agent havinga hydroxyl group. The silicone-series leveling agent may have aproportion of about 0.5 to 5 parts by weight relative to 100 parts byweight of the cationic curable silicone resin.

Another aspect of the present invention provides a shaped productcomprising a hardcoat layer that is a cured product of the curablecomposition. The shaped product may comprise the hardcoat layer aloneand have an average thickness of 10 to 200 μm. The shaped product mayfurther comprise a transparent substrate layer, and the transparentsubstrate layer may have a side provided with the hardcoat layer. Thesheet-like shaped product (or shaped product sheet) may be produced by aroll-to-roll system. The shaped product may comprise the hardcoat layerand a three-dimensional base (or shaped article).

Advantageous Effects of Invention

According to the present invention, the combination use of a specificcationic curable silicone resin and a leveling agent improves surfacehardness and abrasion resistance of a cured product thereof. The resincomposition imparts an excellent surface smoothness, a hightransparency, and an improved external appearance to a cured product ofthe composition. Moreover, even if the cured product is thick, the curedproduct, which has an excellent flexibility, is preventable from curlingor cracking and producible by a roll-to-roll system; the productionefficiency is improvable. Further, the cured product allows improvementin heat resistance, antifouling property, and sliding property. Thus,the cured product has an excellent durability even in a case where thecured product is used for an electric machine that generates heat. Inaddition, in a case where the cured product is stained with fingerprintsor ink (pen mark), the stain is easily removed (wiped off) from thecured product.

DESCRIPTION OF EMBODIMENTS

[Curable Composition]

The curable composition of the present invention contains a cationiccurable silicone resin and a leveling agent.

(Cationic Curable Silicone Resin)

The cationic curable silicone resin contains a silsesquioxane unit (atrifunctional T unit generally represented by RSiO_(3/2)). Morespecifically, the cationic curable silicone resin contains asilsesquioxane unit represented by the formula (1): R¹SiO_(3/2) (whereinR¹ represents a group containing an epoxy group; a hydrogen atom; or ahydrocarbon group).

In the formula (1), the group containing an epoxy group, represented byR¹, may include a group containing a glycidyl group, or a groupcontaining an alicyclic epoxy group.

The group containing a glycidyl group may include, for example, glycidylgroup; and a glycidyloxyC₁₋₁₀alkyl group, such as glycidyloxymethyl,2-glycidyloxyethyl, 3-glycidyloxypropyl, or 4-glycidyloxybutyl (inparticular, a glycidyloxyC₁₋₄alkyl group).

As the group containing an alicyclic epoxy group, there may be mentionedan epoxyC₅₋₁₂cycloalkyl-straight- or branched-chain C₁₋₁₀alkyl group,for example, an epoxycyclopentylC₁₋₁₀alkyl group, such as2,3-epoxycyclopentylmethyl, 2-(2,3-epoxycyclopentyl)ethyl,2-(3,4-epoxycyclopentyl)ethyl, or 3-(2,3-epoxycyclopentyl)propyl; anepoxycyclohexylC₁₋₁₀alkyl group, such as 3,4-epoxycyclohexylmethyl,2-(3,4-epoxycyclohexyl)ethyl, 3-(3,4-epoxycyclohexyl)propyl, or4-(3,4-epoxycyclohexyl)butyl; and an epoxycyclooctylC₁₋₁₀alkyl group,such as 4,5-epoxycyclooctylmethyl, 2-(4,5-epoxycyclooctyl)ethyl, or3-(4,5-epoxycyclooctyl)propyl.

In the group containing an alicyclic epoxy group, the C₅₋₁₂ cycloalkanering may have a C₁₋₄alkyl group [such as methyl or ethyl (in particular,methyl group)] as a substituent. The group containing an alicyclic epoxygroup having a substituent may include, for example, aC₁₋₄alkyl-epoxyC₅₋₁₂ cycloalkyl-straight- or branched-chain C₁₋₁₀alkylgroup, such as 4-methyl-3,4-epoxycyclohexylmethyl,2-(3-methyl-3,4-epoxycyclohexyl)ethyl,2-(4-methyl-3,4-epoxycyclohexyl)ethyl, 3-(4-methyl-3,4-epoxycyclohexyl)propyl, or 4-(4-methyl-3,4-epoxycyclohexyl)butyl.

These groups, each containing an epoxy group, may be used alone or incombination. Among them, in light of the hardness of the cured product,a preferred one includes a group containing an alicyclic epoxy group,particularly an epoxycyclohexyl-straight- or branched-chain C₁₋₄alkylgroup which may have a C₁₋₄alkyl group (in particular, anepoxycyclohexylC₂₋₄alkyl group, such as 3,4-epoxycyclohexylethyl).

In the formula (1), the hydrocarbon group represented by R¹ may includean alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenylgroup, an aryl group, an aralkyl group, and others.

As the alkyl group, there may be mentioned, for example, a straight- orbranched-chain C₁₋₁₀alkyl group, such as methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, or isopentyl.

The alkenyl group may include, for example, a straight- orbranched-chain C₂₋₁₀alkenyl group, such as vinyl, allyl, or isopropenyl.

As the cycloalkyl group, there may be mentioned, for example, aC₄₋₁₂cycloalkyl group, such as cyclobutyl, cyclopentyl, or cyclohexyl.

The cycloalkenyl group may include a C₅₋₁₂cycloalkenyl group, such ascyclopentenyl or cyclohexenyl, and others.

As the aryl group, there may be mentioned, for example, a C₆₋₂₀arylgroup, such as phenyl or naphthyl.

The aralkyl group may include a C₆₋₂₀aryl-C₁₋₄alkyl group, such asbenzyl, phenethyl, or phenylpropyl, and others.

Each one of these hydrocarbon groups may have a substituent. Thesubstituent may include, but should not be limited to, these hydrocarbongroups, an ether group, an ester group, a carbonyl group, a siloxanegroup, a halogen atom (such as a fluorine atom), a (meth)acryl group, amercapto group, an amino group, and a hydroxyl group. Each one of theether group, the ester group, the carbonyl group, and the siloxane groupmay be a linkage group. Among these substituents, a C₁₋₄alkyl group(such as methyl) and a C₆₋₂₀ aryl group (such as phenyl) are practicallyused.

These hydrocarbon groups may be used alone or in combination. Amongthese hydrocarbon groups, a preferred one includes an alkyl group, analkenyl group, and an aryl group, particularly a C₆₋₂₀aryl group. TheC₆₋₂₀aryl group may be a phenyl group which may have a substituent, suchas methylphenyl (tolyl) or dimethylphenyl (xylyl). As the C₆₋₂₀arylgroup, phenyl group is practically used.

Moreover, in the formula (1), R¹ may be a combination of a plural kindof groups, for example, a combination of the group having an epoxy groupand the hydrocarbon group.

Generally, a silsesquioxane having a complete cage structure (or a fullycondensed silsesquioxane) is formed from only the above-mentionedsilsesquioxane unit, designated as T3 unit. According to the presentinvention, it is preferred to use a cationic curable silicone resinfurther containing a unit represented by the formula (2): R¹SiO(OR²)(wherein R¹ represents a group containing an epoxy group; a hydrogenatom; or a hydrocarbon group; R² represents a hydrogen atom or aC₁₋₄alkyl group). The unit (2) is designated as T2 unit. According tothe present invention, the combination of the T3 unit and the T2 unit ina specific ratio can form a silsesquioxane having an incomplete cagestructure, and the resulting cured product has an improved hardnessprobably due to the incomplete cage structure.

In the formula (2), the group containing an epoxy group and thehydrocarbon group, each represented by R¹, may include the same epoxygroup and hydrocarbon group as those in the formula (1). Preferred epoxygroup and hydrocarbon group are also the same as those of the formula(1).

The C₁₋₄alkyl group represented by R² may include, for example, aC₁₋₄alkyl group, such as methyl, ethyl, propyl, or butyl. These alkylgroups may be used alone or in combination. Among these alkyl groups, aC₁₋₂alkyl group, such as methyl or ethyl (in particular, methyl group),is preferred.

The molar quantity of the T3 silsesquioxane unit (1) may be 5 times ormore (for example, 5 to 20 times) as large as that of the T2 unit (2).For example, the molar quantity of the T3 silsesquioxane unit (1) isabout 5 to 18 times, preferably about 6 to 16 times, and more preferablyabout 7 to 15 times (in particular, about 8 to 14 times) as large asthat of the T2 unit (2). In a case where the molar ratio (the T3unit/the T2 unit) is too small, the cured product may have a lowhardness.

According to the present invention, for example, the molar ratio (the T3unit/the T2 unit) can be determined by ²⁹Si-NMR spectroscopy.Specifically, in ²⁹Si-NMR spectrum, the signal (peak) of the siliconatom of the T3 unit and that of the T2 unit are shown at differentpositions (chemical shifts), and the integration (relative area) of thesignal for each peak can give the above-mentioned ratio, the T3 unit/theT2 unit. More specifically, for example, in a case where the group R¹ ofthe formula (1) in the cationic curable silicone resin is2-(3′,4′-epoxycyclohexyl)ethyl group, the signal of the silicon atom ofthe T3 unit is shown in −64 to −70′ ppm and the signal of the siliconatom of the T2 unit is shown in −54 to −60 ppm. Thus in this case, theabove-mentioned ratio (the T3 unit/the T2 unit) can be given bycalculating the ratio of the integration of the signal in −64 to −70 ppm(the T3 unit) relative to the integration of the signal in −54 to −60ppm (the T2 unit).

For example, the ²⁹ Si-NMR spectrum can be measured by the followingapparatus and conditions.

Measuring apparatus: trade name “JNM-ECA500NMR” (manufactured by JEOLLtd.)

Solvent: deuterochloroform

Number of integrations: 1800

Measuring temperature: 25° C.

According to the present invention, the silsesquioxane unit contains theunit (1). The silsesquioxane unit may contain a unit represented by theformula (3): R³ SiO_(3/2) (wherein R³ represents a group containing analicyclic epoxy group) and a unit represented by the formula (4): R⁴SiO_(3/2) (wherein R⁴ represents an aryl group which may have asubstituent) in combination.

The cationic curable silicone resin may contain other monomer units(constitutional units of polyorganosiloxane) in addition to the T unit(i.e., the silsesquioxane unit (1) and the unit (2)). Examples of othermonomer units may include a monofunctional M unit (a unit generallyrepresented by R³ SiO_(1/2)), a difunctional D unit (a unit generallyrepresented by R²SiO_(2/2)), and a tetrafunctional Q unit (a unitgenerally represented by SiO_(4/2)). In each one of the M unit and the Dunit, the organic group represented by R may include the same groups asthose represented by R¹ of the formulae (1) and (2).

The cationic curable silicone resin contains the unit having an epoxygroup (epoxy-containing unit) of not less than 50% by mol (e.g., about50 to 100% by mol), preferably about 55 to 100% by mol (e.g., about 65to 99.9% by mol), and more preferably about 80 to 99% by mol (e.g.,about 90 to 98% by mol) in the total monomer unit [the total (100% bymol in total) of the M unit, the D unit, the T unit, and the Q unitconstituting a polyorganosiloxane structure]. In a case where the ratioof the unit having an epoxy group is excessively small, the curedproduct has a low hardness.

The proportion of the T3 silsesquioxane unit (1) in the total monomerunit may be not less than 50% by mol, for example, about 60 to 99% bymol, preferably about 70 to 98% by mol, and more preferably about 80 to95% by mol (particularly about 85 to 92% by mol). In a case where theproportion of the silsesquioxane unit is too small, the cured productmay have a low hardness probably because it is difficult to form asilsesquioxane having an incomplete cage structure with a moderatemolecular weight.

The total proportion of the silsesquioxane unit (1) and the unit (2)(the total proportion of the difunctional T3 and T2 units) in the totalmonomer unit is, for example, about 60 to 100% by mol, preferably about70 to 100% by mol, and more preferably about 80 to 100% by mol(particularly about 90 to 100% by mol). In a case where the proportionof these units is too small, the cured product may have a low hardnessprobably because it is difficult to form a silsesquioxane having anincomplete cage structure with a moderate molecular weight.

The cationic curable silicone resin may have a cage structure (inparticular, an incomplete cage structure). Whether the cationic curablesilicone resin has a cage (in particular, an incomplete cage)silsesquioxane structure or not can be determined by FT-IR spectroscopy[reference: R. H. Raney, M. Itoh, A. Sakakibara and T. Suzuki, Chem.Rev. 95, 1409 (1995)]. Specifically, a cationic curable silicone resinhaving no intrinsic absorption peak at or near 1050 cm⁻¹ or at or near1150 cm⁻¹ and having one intrinsic absorption peak at or near 1100 cm⁻¹is identifiable as a resin having a cage (in particular, an incompletecage) silsesquioxane structure; a cationic curable silicone resin havingan absorption peak at or near 1050 cm⁻¹ and an absorption peak at ornear 1150 cm⁻¹ is identifiable as a resin having a ladder isilsesquioxane structure. According to the present invention, the FT-IRspectrum can be measured by the following apparatus and conditions.

Measuring apparatus: trade name “FT-720” (manufactured by Horiba, Ltd.)

Measuring method: transmission method

Resolution: 4 cm⁻¹

Measuring wave number range: 400 to 4000 cm⁻¹

Number of integrations: 16

For the molecular weight of the cationic curable silicone resin, theresin has a number average molecular weight (Mn) of about 1000 to 3000,preferably about 1000 to 2800, and more preferably about 1100 to 2600(particularly about 1500 to 2500) in terms of standard polystyrene in agel permeation chromatography. A cured product obtainable from acationic curable silicone resin having an excessively small molecularweight has low abrasion resistance and a low heat resistance. A cationiccurable silicone resin having an excessively large molecular weight hasa low compatibility with other components in the composition, and thus acured product obtainable from the resin has a low heat resistance.

For the molecular weight distribution (Mw/Mn) of the cationic curablesilicone resin, for example, the resin has a molecular weightdistribution (molecular weight dispersity) of about 1 to 3, preferablyabout 1.1 to 2, and more preferably about 1.2 to 1.9 (particularly about1.3 to 1.8) in terms of standard polystyrene in a gel permeationchromatography. Ina case where the molecular weight distribution is toolarge, the cured product may have a low hardness. In contrast, acationic curable silicone resin having an excessively small molecularweight distribution may be hard to handle, because the resin has anincreased viscosity or is in the solid state.

According to the present invention, the number average molecular weightand the molecular weight distribution of the cationic curable siliconeresin can be measured by the following apparatus and conditions.

Measuring apparatus: trade name “LC-20AD” (manufactured by ShimadzuCorporation)

Column: Shodex KF-801 (two columns), KF-802, and KF-803 (manufactured byShowa Denko K.K.)

Measuring temperature: 40° C.

Eluent: THF, sample concentration of 0.1 to 0.2% by weight

Flow volume: 1 mL/minute

Detector: UV-VIS detector (trade name “SPD-20A”, manufactured byShimadzu Corporation)

Molecular weight: in terms of standard polystyrene

The 5% weight loss temperature (T_(d5)) of the cationic curable siliconeresin under an atmosphere of air is not particularly limited to aspecific one, and may be not lower than 330° C. (e.g., about 330 to 450°C.). The 5% weight loss temperature (T_(d5)) is preferably not lowerthan 340° C. (e.g., about 340 to 420° C.) and more preferably not lowerthan 350° C. (e.g., about 350 to 400° C.). In a case where the 5% weightloss temperature is too low, the cured product may have a low heatresistance. In particular, the 5% weight loss temperature can beadjusted to not lower than 330° C. by providing a cationic curablesilicone resin having a T3/T2 unit molar ratio of not less than 5, anumber average molecular weight of 1000 to 3000, a molecular weightdistribution of 1 to 3, and one intrinsic peak at or near 1100 cm⁻¹ inFT-IR spectrum. The 5% weight loss temperature, at which 5% of theinitial weight is lost under a constant rate of heating, is used as anindex of the heat resistance. According to the present invention, the 5%weight loss temperature can be measured under an atmosphere of air at aheating rate of 5° C./minute by TGA (thermogravimetric analysis).

(Process for Producing Cationic Curable Silicone Resin)

The cationic curable silicone resin can be produced by a commonly usedprocess for producing a polyorganosiloxane. The process is notparticularly limited to a specific one. For example, the cationiccurable silicone resin may be produced by hydrolytically condensing oneor more monomers (hydrolyzable silane compounds). As each one of thehydrolyzable silane compounds, there may be used a compoundcorresponding to each one of the units described above.

Specifically, a monomer represented by R¹SiX₃ may be used as a monomercorresponding to the T unit represented by the formula (1) or (2); amonomer represented by (R¹)₃SiX may be used as a monomer correspondingto the M unit; a monomer represented by (R¹)₂SiX₂ may be used as amonomer corresponding to the D unit; a monomer represented by SiX₄ maybe used as a monomer corresponding to the Q unit. Among these monomers,at least the monomer corresponding to the T unit is used. According toan object structure, the monomer may be used in combination with othermonomers.

In the formulae of the monomers described above, R¹ is the same as R¹ ofthe formula (1), and X represents a hydrolytically condensable group.The hydrolytically condensable group represented by X may include, forexample, a halogen atom (such as fluorine, chlorine, bromine, or iodineatom) and an alkoxy group (e.g., a C₁₋₄alkoxy group, such as methoxy orethoxy). Among them, a C₁₋₂alkoxy group (in particular, methoxy group)is practically used.

In a case where two or more monomers are used in combination, thesehydrolyzable silane compounds may be hydrolytically condensedsimultaneously or consecutively. For the consecutive reaction, the orderof reactions is not particularly limited to a specific one.

The hydrolytic condensation of each one of the hydrolyzable silanecompounds may be carried out in the absence of a solvent. The hydrolyticcondensation is preferably carried out in the presence of a solvent. Thesolvent may include, for example, an aromatic hydrocarbon (such asbenzene, toluene, xylene, or ethylbenzene); an ether (such as diethylether, dimethoxyethane, tetrahydrofuran, or dioxane); a ketone (such asacetone, methyl ethyl ketone, or methyl isobutyl ketone); an ester (suchas methyl acetate, ethyl acetate, isopropyl acetate, or butyl acetate);an amide (such as N, N-dimethylformamide or N, N-dimethylacetamide); anitrile (such as acetonitrile, propionitrile, or benzonitrile; and analcohol (such as methanol, ethanol, isopropyl alcohol, or butanol).These solvents may be used alone or in combination. Among thesesolvents, a ketone (such as acetone) and an ether (such as dioxane) arepreferred.

The amount of the solvent is not particularly limited to a specific one.The amount of the solvent can be selected from the range of about 0 to2000 parts by weight (for example, about 100 to 1000 parts by weight)relative to 100 parts by weight of the total monomer according to thereaction time or other factors.

The hydrolytic condensation of the hydrolyzable silane compound mayproceed in the presence of a catalyst and water. The catalyst may be anacid catalyst or may be an alkaline catalyst. The acid catalyst mayinclude, for example, a mineral acid (such as hydrochloric acid,sulfuric acid, nitric acid, phosphoric acid, or boric acid); a phosphateester; a carboxylic acid (such as formic acid, acetic acid, ortrifluoroacetic acid); a sulfonic acid (such as methanesulfonic acid,trifluoromethanesulfonic acid, or p-toluenesulfonic acid); a solid acid(such as active clay); and a Lewis acid (such as iron chloride). Thealkaline catalyst may include, for example, an alkali metal hydroxide(such as sodium hydroxide or potassium hydroxide); an alkaline earthmetal hydroxide (such as magnesium hydroxide or calcium hydroxide); analkali metal carbonate (such as sodium carbonate or potassiumcarbonate); an alkaline earth metal carbonate (such as magnesiumcarbonate); an alkali metal hydrogencarbonate (such as sodiumhydrogencarbonate or potassium hydrogencarbonate); a salt of an organicacid with an alkali metal (such as sodium acetate or potassium acetate);a salt of an organic acid with an alkaline earth metal (such asmagnesium acetate); an alkali metal alkoxide (such as sodium methoxideor sodium ethoxide); an alkali metal phenoxide (such as sodiumphenoxide); an amine (such as triethylamine, N-methylpiperidine,1,8-diazabicyclo[5.4.0]undeca-7-ene, or1,5-diazabicyclo[4.3.0]nona-5-ene); and a nitrogen-containing aromaticheterocyclic compound (such as pyridine, 2,2′-bipyridyl, or1,10-phenanthroline). These catalysts may be used alone or incombination. These catalysts may be used in a state dissolved ordispersed in water or a solvent.

The amount to be used of the solvent is not particularly limited to aspecific one. The amount of the solvent may selected from the range ofabout 0.002 to 0.2 mol (in particular, about 0.005 to 0.1 mol) relativeto 1 mol of the total amount of the hydrolyzable silane compound.

The amount to be used of water is not particularly limited to a specificone. The amount of water may be selected from the range of about 0.5 to20 mol (for example, about 1 to 15 mol) relative to 1 mol of the totalamount of the hydrolyzable silane compound. The method of adding wateris not particularly limited to a specific one. The total amount (thetotal amount to be used) of water may be added at a time or stepwise.The stepwise addition may be continuous or intermittent.

For the reaction conditions of the hydrolytic condensation, it ispreferred to select the reaction conditions by which a cationic curablesilicone resin having the above-mentioned constitutional units isobtainable. The reaction temperature of the hydrolytic condensation isnot particularly limited to a specific one and, for example, is about 40to 100° C. (in particular, about 45 to 80° C.). The control of thereaction temperature within this range efficiently allows easyadjustment of the constitutional unit of the resin to theabove-mentioned range. The reaction time is not particularly limited toa specific one and, for example, is about 0.1 to 10 hours (inparticular, about 1.5 to 8 hours). The reaction may be carried out underan atmospheric pressure or may be carried out under an applied pressureor a reduced pressure. The atmosphere of the reaction may include, butshould not be limited to, an active gas atmosphere containing oxygen(such as air), preferably an inactive gas atmosphere (such as nitrogenor argon).

The hydrolytic condensation of the hydrolyzable silane compound providesa polyorganosiloxane (silicone resin) containing apolyorganosilsesquioxane unit. After the completion of the hydrolyticcondensation, the catalyst is preferably neutralized in order to inhibitthe opening of the epoxy group of the resin. Moreover, the resultingsilicone resin may be separated and purified by, for example, aseparation means, such as water washing, acid washing, alkali washing,filtration, concentration, distillation, extraction, crystallization,recrystallization, or column chromatography, or a combination thereof.

(Leveling Agent)

As the leveling agent, there may be used a commonly used leveling agent(e.g., an ethylene oxide adduct of acetylene glycol) as far as theleveling agent has a capability to reduce a surface tension. In light ofan excellent capability to reduce a surface tension, the leveling agentmay preferably include a silicone-series leveling agent and afluorine-containing leveling agent. According to the present invention,the combination use of the cationic curable silicone resin and theleveling agent allows the improvement of the surface smoothness, thetransparency or luster (external appearance), the sliding property, andothers. Not only does the use of a specific leveling agent allow themaintenance of the hardness or abrasion resistance, but the control ofthe blending ratio also allows the improvement of the hardness orabrasion resistance.

The silicone-series leveling agent includes a leveling agent having apolyorganosiloxane skeleton. As the polyorganosiloxane skeleton, theremay be used a polyorganosiloxane having the M unit, the D unit, the Tunit, and/or the Q unit, as with the cationic curable silicone resin.Generally, a polyorganosiloxane having the D unit is used. Thepolyorganosiloxane may have an organic group (R) selected from among thehydrocarbon groups exemplified as the group R¹ of the formula (1) of thecationic curable silicone resin. The organic group R usually includes aC₁₋₄alkyl group and/or an aryl group, preferably methyl group and/orphenyl group (in particular, methyl group). The repeating number ofsiloxane units (the degree of polymerization) is, for example, about 2to 3000, preferably about 3 to 2000, and preferably about 5 to 1000.

The fluorine-containing leveling agent includes a leveling agent havinga fluoroaliphatic hydrocarbon skeleton. As the fluoroaliphatichydrocarbon skeleton, for example, there may be mentioned afluoroC₁₋₁₀alkane, such as fluoromethane, fluoroethane, fluoropropane,fluoroisopropane, fluorobutane, fluoroisobutane, fluoro-t-butane,fluoropentane, or fluorohexane.

Each one of these fluoroaliphatic hydrocarbon skeletons has one or morefluorine atoms substituted in place of one or more hydrogen atoms on theparent skeleton. In order to improve the abrasion resistance, thesliding property, and the antifouling property, a perfluoroaliphatichydrocarbon skeleton, in which all hydrogen atoms on the parent skeletonare replaced with fluorine atoms, is preferred.

The fluoroaliphatic hydrocarbon skeleton may have a polyfluoroalkyleneether skeleton, which is a repeating unit through an ether bond. Thefluoroaliphatic hydrocarbon group as the repeating unit may be at leastone member selected from the group consisting of fluoroC₁₋₄alkylenegroups, for example, fluoromethylene, fluoroethylene, fluoropropylene,and fluoroisopropylene. These fluoroaliphatic hydrocarbon groups may bethe same or different from each other. The repeating number offluoroalkylene ether units (the degree of polymerization) may be, forexample, about 10 to 3000, preferably about 30 to 1000, and morepreferably about 50 to 500.

Among these skeletons, the polyorganosiloxane skeleton is preferred inlight of the excellent affinity with the cationic curable siliconeresin.

In order to impart various functions to the cationic curable siliconeresin, the leveling agent having such a skeleton may have a functionalgroup (such as a hydrolytically condensable group, or a reactive groupto an epoxy group), a radical-polymerizable group, a polyether group, apolyester group, and/or a polyurethane group. The silicone-seriesleveling agent may have a fluoroaliphatic hydrocarbon group, or thefluorine-containing leveling agent may have a polyorganosiloxane group.

The hydrolysable group may include, for example, hydroxysilyl group; atrihalosilyl group (such as trichlorosilyl); a dihaloC₁₋₄alkylsilylgroup (such as dichloromethylsilyl); a dihaloaryl group (such asdichlorophenylsilyl); a halodiC₁₋₄alkylsilyl group (e.g., achlorodiC₁₋₄alkylsilyl, such as chlorodimethylsilyl); atriC₁₋₄alkoxysilyl group (such as trimethoxysilyl or triethoxysilyl); adiC₁₋₄alkoxyC₁₋₄alkylsilyl group (such as dimethoxymethylsilyl ordiethoxymethylsilyl); a diC₁₋₄alkoxyarylsilyl group (such asdimethoxyphenylsilyl or diethoxyphenylsilyl); aC₁₋₄alkoxydiC₁₋₄alkylsilyl group (such as methoxydimethylsilyl orethoxydimethylsilyl); a C₁₋₄alkoxydiarylsilyl group (such asmethoxydiphenylsilyl or ethoxydiphenylsilyl); and aC₁₋₄alkoxyC₁₋₄alkylarylsilyl group (such as methoxymethylphenylsilyl orethoxymethylphenylsilyl). Among them, a preferred one includes atriC₁₋₄alkoxysilyl group, such as trimethoxysilyl group, in light of thereactivity or others.

The reactive group to an epoxy group may include, for example, ahydroxyl group, an amino group, a carboxyl group, an acid anhydridegroup (such as maleic anhydride group), and an isocyanate group. Amongthem, a group to be widely used includes a hydroxyl group, an aminogroup, an acid anhydride group, and an isocyanate group in light of thereactivity or others. In view of easiness of handling or obtaining, ahydroxyl group is preferred.

The radical-polymerizable group may include, for example, a(meth)acryloyloxy group and a vinyl group. Among them, a(meth)acryloyloxy group is practically used.

As the polyether group, for example, there may be mentioned apolyoxyC₂₋₄alkylene group, such as a polyoxyethylene group, apolyoxypropylene group, a polyoxybutylene group, or apolyoxyethylene-polyoxypropylene group. In the polyether group, therepeating number of oxyalkylene groups (the mole number of oxyalkylenegroups added) is, for example, about 2 to 1000, preferably about 3 to100, and preferably about 5 to 50. Among them, a preferred one includesa polyoxyC₂₋₃alkylene group, such as a polyoxyethylene or apolyoxypropylene (in particular, a polyoxyethylene group).

The polyester group may include, for example, a polyester groupobtainable by a reaction of a dicarboxylic acid [e.g., an aromaticcarboxylic acid (such as terephthalic acid) or an aliphatic carboxylicacid (such as adipic acid)] and a diol (e.g., an aliphatic diol, such asethylene glycol) and a polyester group obtainable by a ring openingpolymerization of a circular ester (e.g., a lactone, such ascaprolactone).

The polyurethane group may include, for example, a commonly usedpolyester-based polyurethane group and a polyether-based polyurethanegroup.

Each one of these functional groups may be introduced into thepolyorganosiloxane skeleton or the fluoroaliphatic hydrocarbon skeletonby a direct bonding or through a linkage group (for example, an alkylenegroup, a cycloalkylene group, an ether group, an ester group, an amidegroup, a urethane group, or a linkage group having a plurality of theabove-mentioned groups).

Among these functional groups, a preferred one includes a hydrolyticallycondensable group and a reactive group to an epoxy group in the respectthat the functional group can be allowed to react with the cationiccurable silicone resin to improve the hardness of the cured product. Thereactive group to an epoxy group (in particular, hydroxyl group) isparticularly preferred.

The hydroxyl group may be a terminal hydroxyl group of a(poly)oxyalkylene group [such as a (poly)oxyethylene group]. Theleveling agent having a hydroxyl group may include, for example, asilicone-series leveling agent (e.g., apolydimethylsiloxanepolyoxyethylene) having a (poly)oxyC₂₋₃alkylenegroup (such as a (poly)oxyethylene group) on a side chain of apolyorganosiloxane skeleton (such as a polydimethylsiloxane); and afluorine-containing leveling agent (e.g., a fluoroalkylpolyoxyethylene)having a fluoroaliphatic hydrocarbon group on a side chain of a(poly)oxyC₂₋₃alkylene skeleton (such as a (poly)oxyethylene).

As the silicone-series leveling agent, there may be used a commerciallyavailable silicone-series leveling agent. The commercially availablesilicone-series leveling agent may include, for example, a BYK seriesleveling agent manufactured by BYK Japan KK (e.g., “BYK-300”,“BYK-301/302”, “BYK-306”, “BYK-307”, “BYK-310”, “BYK-315”, “BYK-313”,“BYK-320”, “BYK-322”, “BYK-323”, “BYK-325”, “BYK-330”, “BYK-331”,“BYK-333”, “BYK-337”, “BYK-341”, “BYK-344”, “BYK-345/346”, “BYK-347”,“BYK-348”, “BYK-349”, “BYK-370”, “BYK-375”, “BYK-377”, “BYK-378”,“BYK-UV3500”, “BYK-UV3510”, “BYK-UV3570”, “BYK-3550”,“BYK-SILCLEAN3700”, and “BYK-SILCLEAN3720”), an AC series leveling agentmanufactured by Algin Chemie (e.g., “AC FS180”, “AC FS360”, and “ACS20”), a POLYFLOW series leveling agent manufactured by KyoeishaChemical Co., Ltd. (e.g., “POLYFLOW KL-400X”, “POLYFLOW KL-400HF”,“POLYFLOW KL-401”, “POLYFLOW KL-402”, “POLYFLOW KL-403”, and“POLYFLOWKL-404”), aKP series levelingagentmanufactured by Shin-EtsuChemical Co., Ltd. (e.g., “KP-323”, “KP-326”, “KP-341”, “KP-104”,“KP-110”, and“KP-112”) and a leveling agent manufactured by Dow CorningToray Co., Ltd. (e.g., “LP-7001”, “LP-7002”, “8032ADDITIVE”,“57ADDITIVE”, “L-7604”, “FZ-2110”, “FZ-2105”, “67ADDITIVE”,“8618ADDITIVE”, “3ADDITIVE”, and “56ADDITIVE”).

As the fluorine-containing leveling agent, there may be used acommercially available fluorine-containing leveling agent. Thecommercially available fluorine-containing leveling agent may include,for example, an OPTOOL series leveling agent manufactured by DaikinIndustries, Ltd. (“DSX”, “DAC-HP”), a SURFLON series leveling agentmanufactured by AGC Seimi Chemical Co., Ltd. (e.g., “S-242”, “S-243”,“S-420”, “S-611”, “S-651”, and “S-386”), a BYK series leveling agentmanufactured by BYK Japan KK (e.g., “BYK-340”), an AC series levelingagent manufactured by Algin Chemie (e.g., “AC 110a” and “AC 100a”), aMEGAFACE series leveling agent manufactured by DIC Corporation (e.g.,“MEGAFACE F-114”, “MEGAFACE F-410”, “MEGAFACE F-444”, “MEGAFACE EXPTP-2066”, “MEGAFACE F-430”, “MEGAFACE F-472SF”, “MEGAFACE F-477”,“MEGAFACE F-552”, “MEGAFACE F-553”, “MEGAFACE F-554”, “MEGAFACE F-555”,“MEGAFACE R-94”, “MEGAFACE RS-72-K”, “MEGAFACE RS-75”, “MEGAFACE F-556”,“MEGAFACE EXP TF-1367”, “MEGAFACE EXP TF-1437”, “MEGAFACE F-558”, and“MEGAFACE EXP TF-1537”, a FC series leveling agent manufactured bySumitomo 3M Limited (e.g., “FC-4430” and “FC-4432”), a FTERGENT seriesleveling agent manufactured by Neos Company Limited (e.g., “FTERGENT100”, “FTERGENT 100C”, “FTERGENT 110”, “FTERGENT 150”, “FTERGENT 150CH”,“FTERGENT A-K”, “FTERGENT 501”, “FTERGENT 250”, “FTERGENT 251”,“FTERGENT 222F”, “FTERGENT 208G”, “FTERGENT 300”, “FTERGENT 310”, and“FTERGENT 400SW”), and a PF series leveling agent manufactured byKitamura Chemicals Co., Ltd. (e.g., “PF-136A”, “PF-156A”, “PF-151N”,“PF-636”, “PF-6320”, “PF-656”, “PF-6520”, “PF-651”, “PF-652”, and“PF-3320”).

These leveling agents may be used alone or in combination. For example,a plural kind of the silicone-series leveling agents may be used incombination, a plural kind of the fluorine-containing leveling agentsmay be used in combination, or the silicone-series leveling agent andthe fluorine-containing leveling agent may be used in combination. Amongthese leveling agents, a silicone-series leveling agent having ahydroxyl group is preferred, since the leveling agent has an excellentaffinity with the cationic curable silicone resin, can be allowed toreact with an epoxy group, and can improve the hardness or externalappearance of the cured product.

The silicone-series leveling agent having a hydroxyl group may include,for example, a polyether-modified polyorganosiloxane, in which a mainchain or side chain of a polyorganosiloxane skeleton (such as apolydimethylsiloxane) has a polyether group; a polyester-modifiedpolyorganosiloxane, in which a main chain or side chain of apolyorganosiloxane skeleton has a polyester group; and asilicone-modified (meth)acrylic resin, in which a (meth)acrylic resin ismodified with a polyorganosiloxane. For each one of these levelingagents, the polyorganosiloxane skeleton may have a hydroxyl group, orthe polyether group, the polyester group, or the (meth)acryloyl groupmay have a hydroxyl group. As the leveling agent, for example, there maybe used “BYK-370”, “BYK-SILCLEAN3700”, “BYK-SILCLEAN3720” manufacturedby BYK Japan KK.

The ratio of the leveling agent relative to 100 parts by weight of thecationic curable silicone resin can be selected from the range of about0.01 to 20 parts by weight, and, for example, is about 0.05 to 15 partsby weight, preferably about 0.1 to 10 parts by weight, and morepreferably about 0.2 to 5 parts by weight. The leveling agent in anexcessively small ratio may decrease the surface smoothness of the curedproduct. The leveling agent in an excessively large ratio may decreasethe hardness of the cured product.

In particular, the ratio of the silicone-series leveling agent relativeto 100 parts by weight of the cationic curable silicone resin may be,for example, about 0.1 to 10 parts by weight, preferably about 0.2 to 5parts by weight (e.g., about 0.3 to 3 parts by weight), and morepreferably about 0.5 to 2 parts by weight (particularly about 0.8 to 1.5parts by weight). The ratio of the fluorine-containing leveling agentrelative to 100 parts by weight of the cationic curable silicone resinmay be, for example, about 0.05 to 5 parts by weight, preferably about0.1 to 3 parts by weight (e.g., about 0.15 to 2 parts by weight), andmore preferably about 0.2 to 1 part by weight (particularly about 0.3 to0.8 parts by weight). The ratio adjustment of the leveling agent withinsuch a range can improve not only the surface smoothness of the curedproduct but also the hardness of the cured product; it has not beenexpected before that the leveling agent improves the hardness of thecured product.

(Cationic Polymerization Initiator)

The curable composition of the present invention preferably furthercontains a cationic polymerization initiator (an acid generator) inorder to promote the polymerization and improve the hardness of thecured product. As the cationic polymerization initiator, there may beused a commonly used photoacid generator or a commonly used thermal acidgenerator, according to the kind of the polymerization.

The photoacid generator may include, for example, a sulfonium salt (asalt of a sulfonium ion and an anion), an iodonium salt (a salt of aniodonium ion and an anion), a selenium salt (a salt of a selenium ionand an anion), an ammonium salt (a salt of an ammonium ion and ananion), a phosphonium salt (a salt of a phosphonium ion and an anion),and a salt of a transition metal complex ion and an anion. Thesephotoacid generators may be used alone or in combination. Among thesephotoacid generators, an acid generator having a high acidity, e.g., asulfonium salt, is preferred in light of the improvement of thereactivity and the improvement of the hardness of the cured product.

The sulfonium salt may include, for example, a triarylsulfonium salt[such as a triphenylsulfonium salt, a tri-p-tolylsulfonium salt, atri-o-tolylsulfonium salt, a tris(4-methoxyphenyl)sulfonium salt, a1-naphthyldiphenylsulfonium salt, a 2-naphthyldiphenylsulfonium salt, atris(4-fluorophenyl)sulfonium salt, a tri-1-naphthylsulfonium salt, atri-2-naphthylsulfonium salt, a tris(4-hydroxyphenyl)sulfonium salt, adiphenyl[4-(phenylthio)phenyl]sulfonium salt, or a4-(p-tolylthio)phenyldi-(p-phenyl)sulfonium salt]; a diarylsulfoniumsalt (such as a diphenylphenacylsulfonium salt, adiphenyl-4-nitrophenacylsulfonium salt, a diphenylbenzylsulfonium salt,or a diphenylmethylsulfonium salt); a monoarylsulfonium salt (such as aphenylmethylbenzylsulfonium salt, a 4-hydroxyphenylmethylbenzylsulfoniumsalt, or a 4-methoxyphenylmethylbenzylsulfonium salt); and atrialkylsulfonium salt (such as a dimethylphenacylsulfonium salt, aphenacyltetrahydrothiophenium salt, or a dimethylbenzylsulfoniumsalt).These sulfoniumsaltsmay be used alone or in combination. Among thesesulfonium salts, a triarylsulfonium salt is preferred.

The anion (counter ion) for forming a salt with a cation may include,for example, SbF⁶⁻, PF⁶⁻, BF⁴⁻, a fluoroalkylfluorophosphate ion [suchas (CF₃CF₂)₃PF³⁻ or (CF₃CF₂CF₂)₃PF³], (C₆F₅)₄B⁻, (C₆F₅)₄Ga⁻, a sulfonateanion (such as trifluoromethanesulfonate anion,pentafluoroethanesulfonate anion, nonafluorobutanesulfonate anion,methanesulfonate anion, benzenesulfonate anion, or p-toluenesulfonateanion), (CF₃SO₂)₃C⁻, (CF₃SO₂)₂N⁻, a perhalogenate ion, a halosulfonateion, a sulfate ion, a carbonate ion, an aluminate ion, ahexafluorobismuthate ion, a carboxylate ion, an arylborate ion, athiocyanate ion, and a nitrate ion. Among these anions, afluoroalkylfluorophosphate ion is preferred in light of solubility andothers.

As the photoacid generator, a commercially available photoacid generatormay be used. The commercially available photoacid generator may include,for example, a photoacid generator manufactured by San-Apro Ltd., suchas “HS-1”, “HS-1A”, “HS-1P”, “HS-1N”, “HS-1TF”, “HS-1NF”, “HS-1MS”,“HS-1CS”, “HS-1PC”, “LW-S1”, “LW-S1NF”, “K1-S”, “CPI-101A”, “CPI-100P”,or“CPI300PG”.

The thermal acid generator may include, for example, an arylsulfoniumsalt, an aryliodonium salt, an allene-ion complex, a quaternary ammoniumsalt, an aluminum chelate, and a boron trifluoride amine complex. Thesethermal acid generators may be used alone or in combination. Among thesethermal acid generators, an acid generator having a high acidity, e.g.,an arylsulfonium salt, is preferred in light of the improvement of thereactivity and the improvement of the hardness of the cured product. Asthe anion, there may be mentioned anions as described in the photoacidgenerator. The anion may be an antimony fluoride ion, such as SbF⁶⁻.

As the thermal acid generator, a commercially available thermal acidgenerator may be used. The commercially available thermal acid generatormay include, for example, a thermal acid generator manufactured bySanshin Chemical Industry Co., Ltd. (such as “SAN-AID SI-60L”, “SAN-AIDSI-60S”, “SAN-AID SI-80L”, or “SAN-AID SI-100L”) and a thermal acidgenerator manufactured by ADEKA Corporation (such as “SP-66” or“SP-77”).

The ratio of the cationic polymerization initiator relative to 100 partsby weight of the cationic curable silicone resin can be selected fromthe range of about 0.01 to 10 parts by weight, and is, for example,about 0.05 to 5 parts by weight, preferably about 0.1 to 3 parts byweight, and more preferably about 0.3 to 2 parts by weight (particularlyabout 0.5 to 1.5 parts by weight). An excessively small ratio of thecationic polymerization initiator may decelerate the progress of thecuring reaction, resulting in a low hardness of the cured product. Anexcessively large ratio of the cationic polymerization initiator maydecrease the storage stability of the composition or may cause thecoloration of the cured product.

(Other Additives)

The curable composition may contain another curable resin. Anothercurable resin may include, for example, an epoxy resin, an oxetaneresin, and a vinyl ether resin. These curable resins may be used aloneor in combination. Among these curable resins, an epoxy resin ispreferred in view of reactivity, miscibility, and others. As the epoxyresin, there may be mentioned, for example, a glycidyl ether-based epoxyresin, a glycidyl ester-based epoxy resin, an alicyclic epoxy resin, aglycidylamine-based epoxy resin, and a long-chain aliphatic epoxy resin.Among these epoxy resins, an alicyclic epoxy resin is particularlypreferred in light of a low viscosity and an excellent sliding property.The ratio of another curable resin relative to 100 parts by weight ofthe cationic curable silicone resin is about not more than 100 parts byweight, for example, about not more than 50 parts by weight (e.g., about1 to 50 parts by weight), preferably about not more than 30 parts byweight (e.g., about 5 to 30 parts by weight).

The curable composition may contain a commonly used additive as far asthe additive does not have a bad influence on abrasion resistance ortransparency. The commonly used additive may include, for example, acuring agent (or a hardener) (e.g., an amine-series curing agent, apolyaminoamide-series curing agent, an acid anhydride-series curingagent, and a phenol-series curing agent), a curing accelerator (e.g., animidazole compound, an alkali metal or alkaline earth metal alkoxide, aphosphine compound, an amide compound, a Lewis acid complex compound, asulfur compound, a boron compound, and a condensable organic metalcompound), a filler (e.g., an inorganic filler, such as titanium oxideor alumina), a stabilizer (e.g., an antioxidant, an ultravioletabsorber, a light stabilizer, and a heat stabilizer), a plasticizer, alubricant, an antifoaming agent, an antistatic agent, and a flameretardant. These additives may be used alone or in combination. Theratio of the additive(s) relative to 100 parts by weight of the cationiccurable silicone resin is about not more than 100 parts by weight, forexample, about not more than 30 parts by weight (e.g., about 0.01 to 30parts by weight) and preferably about not more than 10 parts by weight(e.g., about 0.1 to 10 parts by weight).

The curable composition may further contain an organic solvent, forexample, a ketone (such as acetone, methyl ethyl ketone, methyl isobutylketone, or cyclohexanone), an ether (such as dioxane ortetrahydrofuran), an aliphatic hydrocarbon (such as hexane), analicyclic hydrocarbon (such as cyclohexane), an aromatic hydrocarbon(such as benzene), a halocarbon (such as dichloromethane ordichloroethane), an ester (such as methyl acetate or ethyl acetate),water, an alcohol (such as ethanol, isopropanol, butanol, orcyclohexanol), a cellosolve (such as methyl cellosolve or ethylcellosolve), a cellosolve acetate, and an amide (such asdimethylformamide or dimethylacetamide).

The curable composition may have a solid content weight of, for example,about 1 to 80% by weight, preferably about 5 to 50% by weight, and morepreferably about 10 to 30% by weight.

[Shaped Product]

The shaped product of the present invention contains a hardcoat layercontaining (or formed from) the cured product of the curablecomposition.

The shaped product of the present invention may contain the hardcoatlayer alone. For example, the shaped product may be a thick sheet (ahardcoat sheet), which may be used as a substitute for glass. Thehardcoat sheet may be used as a light-guiding sheet (a substitute forglass) useful for various optical applications due to excellenttransparency and heat resistance, and others. Examples of the opticalapplications may include a television; a personal computer; a display(such as a liquid crystal display or an organic electroluminescent (EL)display) for a personal digital assistance (e.g., a game machine, atablet computer, a smart phone, and a mobile phone); a solar cell; and awindow of a vehicle (such as an automobile) or a building. The shapedproduct sheet may have an average thickness of, for example, not lessthan 10 μm (e.g., about 10 to 1000 μm), e.g., about 100 to 900 μm,preferably about 200 to 800 μm, and more preferably about 300 to 700 μm(particularly about 400 to 600 μm).

The shaped product of the present invention may comprise atwo-dimensional or three-dimensional base (or shaped article) having thehardcoat layer directly or indirectly formed on a surface thereof.

The two-dimensional base (or shaped article) may be in the form of afilm or a sheet. The film (or film-like base or substrate film) may havethe hardcoat layer on at least one side thereof. The film may have thehardcoat layer on one side thereof or may have the hardcoat layer oneach side thereof. The two-dimensional base may be formed from anorganic material (such as a thermoplastic resin or a thermosettingresin) or an inorganic material (such as a metal, a glass, or aceramics). As the base, a transparent substrate film (a transparentsubstrate layer) is preferred, since the hardcoat layer, which is acured product of the curable composition of the present invention, hasan excellent transparency.

The transparent substrate film is formed from a plastic. The plastic maybe a thermosetting resin. The transparent substrate film for which thehardcoat layer is necessary is usually formed from a thermoplastic resinin practical cases. The thermoplastic resin may include, for example, anolefinic resin, a styrenic resin, a polyester-series resin, apolyamide-series resin, a vinyl chloride-series resin, apolycarbonate-series resin, a poly(vinyl alcohol)-series resin, apolyimide-series resin, a polysulfone-series resin, a poly(phenyleneether)-series resin, a poly(phenylene sulfide)-series resin, a celluloseester-series resin, and a fluorine-containing resin. These plastics maybe used alone or in combination. Among these plastics, in light ofwell-balanced properties, such as transparency and mechanicalproperties, a preferred one includes a polyester-series resin [e.g., ahomo- or co-poly(alkylene arylate)-series resin containing aC₂₋₄alkyleneC₆₋₁₂arylate unit, such as a poly(ethylene terephthalate)(PET), a poly(butylene terephthalate) (PBT), or a poly(ethylenenaphthalate) (PEN)] and a polycarbonate-series resin (e.g., a bisphenolA-based polycarbonate).

The transparent substrate film may be a single-layer film or may be alaminate film. The laminate film may have a plurality of the same typeresin layers or may have a plurality of layers different in type fromeach other.

The transparent substrate film may be a non-stretched film or may be astretched (monoaxially or biaxially stretched) film.

The transparent substrate film may have an adhesive layer (an adhesionlayer), such as an anchor coat layer, on a surface thereof in order toimprove the adhesion to the hardcoat layer. The transparent substratefilm may be subjected to a surface treatment, e.g., a dischargetreatment (such as corona discharge or glow discharge), an acidtreatment, and a flame treatment. It is preferred that the surface ofthe transparent substrate film have an anchor coat layer formed from anadhesive or an agglutinant (such as an acrylic resin, a urethane-seriesresin, or a silicone-series resin) or be treated with a coronadischarge. The transparent substrate film may further contain anadhesion improver in order to improve the adhesion.

The transparent substrate film may optionally contain an additive as faras the additive does not decrease the transparency of the transparentsubstrate film. The additive may include a stabilizer (such as anantioxidant, an ultraviolet absorber, a light stabilizer, or a heatstabilizer), a nucleation agent, a flame retardant, a flame-retardantauxiliary, a filler, a plasticizer, an impact modifier, a reinforcer, acoloring agent, a dispersing agent, an antistatic agent, a foamingagent, an antibacterial agent, and others. These additives may be usedalone or in combination.

It is sufficient that the two-dimensional shaped article has a thicknessof about not less than 1 μm without particular limitation. For example,the two-dimensional shaped article may have a thickness of about 1 μm to100 mm, preferably about 20 μm to 10 mm, and more preferably about 50 to1000 μm. The thickness of the transparent substrate film is notparticularly limited to a specific one, and may be, for example, about 1to 300 μm, preferably about 20 to 250 μm, and more preferably about 40to 200 μm (particularly about 50 to 150 μm).

The hardcoat layer to be laminated on the two-dimensional shaped articlehas a thickness of, for example, about 0.1 to 100 μm (e.g., about 5 to50 μm), preferably about 1 to 30 μm, and more preferably about 3 to 20μm (particularly about 4 to 10 μm). A laminated product of a softtwo-dimensional shaped article (such as a transparent substrate layer)and a hardcoat layer having such a thickness has an excellentflexibility, and thus the product can be produced by a roll-to-rollsystem. The product is therefore producible with a high productionefficiency.

The shaped product having the hardcoat layer laminated on the surface ofthe transparent substrate film, which also has an excellenttransparency, can be used for optional applications in the same manneras in the above-mentioned product having the hardcoat layer alone.

Each one of these shaped products (the sheet-like product formed fromthe hardcoat layer alone, and the laminate of the transparent substratelayer and the hardcoat layer) has an excellent transparency.

The shaped product (the hardcoat layer alone, or the laminate of thehardcoat layer and the transparent substrate layer) has a low haze(e.g., at a thickness of 50 μm) due to a high surface smoothness. Theshaped product has a haze, for example, about 0.05 to 5%, preferablyabout 0.1 to 3% (e.g., about 0.15 to 2%), and more preferably about 0.2to 1% (particularly about 0.3 to 0.8%) in accordance with JapaneseIndustrial Standards (JIS) K7136.

The shaped product has a total light transmittance (at a thickness of 50μm) of, for example, about 70 to 100%, preferably about 80 to 100%, morepreferably about 85 to 100% (e.g., about 85 to 98%), and particularlyabout 90 to 100% (e.g., about 90 to 95%) in accordance with JIS K7361.

The three-dimensional base (or shaped article) is not particularlylimited to a specific one and may be a variety of three-dimensionalbases (or shaped articles), each formed from an organic material or aninorganic material. The curable composition of the present invention hasan excellent coating property and can form a uniform hardcoat layer on acomplicated three-dimensional base. In order to improve the adhesion tothe hardcoat layer, the surface of the three-dimensional base may alsobe subjected to a surface treatment in the same manner as in thetransparent substrate film. The hardcoat layer has a thickness of, forexample, about 0.1 to 100 μm (e.g., about 5 to 70 μm), preferably about1 to 60 μm (e.g., about 1 to 30 μm), and more preferably about 10 to 50μm (particularly about 30 to 40 μm).

In the shaped product, the hardcoat layer (the cured product of thecurable composition) has a high surface hardness. The hardcoat layer hasa pencil hardness (under 750 g load) of not lower than 3H (e.g., about3H to 9H), preferably not lower than 4H (e.g., about 4H to 9H), and morepreferably not lower than 5H (particularly about 5H to 9H) in accordancewith JIS K5600. In particular, the hardcoat layer can have a pencilhardness of not lower than 7H (e.g., about 7H to 9H) and preferably notlower than 8H (e.g., about 8H to 9H) by regulating an aging step orothers. The hardcoat layer can obtain a pencil hardness of 9H, which isequivalent to that of a glass. A hardcoat layer with an excessivelysmall pencil hardness has a low abrasion resistance.

The hardcoat layer also has a high abrasion resistance. Even in a casewhere a #0000 steel wool with which a stick 1 cm in diameter is coveredis allowed to go back and forth on the surface of the hardcoat layer 100times under a load of 1.3 kg/cm², scratches do not result on the surfaceof the hardcoat layer.

The hardcoat layer has an excellent surface smoothness. The hardcoatlayer has an arithmetic average roughness Ra of about 0.1 to 20 nm,preferably about 0.1 to 10 nm, and more preferably about 0.1 to 5 nm inaccordance with JIS B0601.

The hardcoat layer also has an excellent surface sliding property. Thehardcoat layer has a contact angle of water against a surface thereof isnot less than 60°, for example, about 60 to 110°, preferably about 70 to110°, and more preferably about 80 to 110°. A hardcoat layer having anexcessively small contact angle of water against a surface thereof may alow abrasion resistance probably due to a low sliding property. Thecontact angle of water can be measured by an automatic dynamic contactangle meter (“Type DCA-UZ” manufactured by Kyowa Interface Science Co.,Ltd.) or other means.

[Process for Producing Shaped Product]

The shaped product (coated shaped product or laminate) of the presentinvention is produced through a step of applying the curable compositionon a support (a releasable support, or a two-dimensional orthree-dimensional base (or shaped article)) and a step of curing thecoated composition.

For the applying step, the method for applying the curable compositionmay include a conventional manner, for example, a roll coater, an airknife coater, a blade coater, a rod coater, a reverse coater, a barcoater, a comma coater, a dip and squeeze coater, a die coater, agravure coater, a microgravure coater, a silkscreen coater, a dippingmethod, a spraying method, and a spinner method. Among these methods, abar coater or a gravure coater is used widely.

In a case where the curable composition contains an organic solvent, orother cases, the curable composition may optionally be dried afterapplying. The curable composition may be dried at a temperature of about40 to 150° C., preferably about 50 to 120° C., and more preferably about60 to 100° C. (particularly about 60 to 80° C.). The drying time is notparticularly limited to a specific one and can be selected from therange of about 30 seconds to one hour. In order to prepare a hardcoatlayer having a pencil hardness equivalent to that of a glass, the dryingtime may be adjusted. The drying time may be not shorter than 3 minutes(e.g., about 3 minutes to one hour), preferably not shorter than 5minutes (e.g., about 5 to 30 minutes), and more preferably not shorterthan 8 minutes (e.g., about 8 to 20 minutes).

In the curing step, the curable composition may be cured by irradiationwith active energy ray (or actinic ray) or by heating, depending on thespecies of the cationic polymerization initiator. Among them, thecurable composition may usually be cured by irradiation with an activeenergy ray.

As the active energy ray, heat and/or a light energy ray may be used. Inparticular, the irradiation with the light energy ray is usable. As thelight energy ray, there may be used a radioactive ray (such as gamma rayor X-ray), an ultraviolet ray, a visible ray, an electron beam (EB), andothers. The light energy ray is usually an ultraviolet ray or anelectron beam in practical cases. In particular, in a case where a sheethaving a high weather resistance is produced, the electron beamirradiation may be used because of polymerization without anypolymerization initiator.

For the ultraviolet ray, the light source may include, for example, aDeep UV lamp, a low-pressure mercury lamp, a high-pressure mercury lamp,a superhigh-pressure mercury lamp, a halogen lamp, and a laser lightsource (a light source, such as a helium-cadmium laser or an excimerlaser). The quantity of the irradiation light (irradiation energy)varies depending on the thickness of the coated layer. The quantity ofthe irradiation light may for example be about 50 to 10000 mJ/cm²,preferably about 70 to 5000 mJ/cm², and more preferably about 100 to1000 mJ/cm². In order to improve the adhesion to the two- orthree-dimensional base, the quantity of light or the irradiation timemay be increased. The quantity of the irradiation light may for examplebe about 300 to 10000 mJ/cm² (particularly about 500 to 5000 mJ/cm²).

For the electron beam, an exposure source (e.g., an electron beamirradiation apparatus) can be used for the electron beam irradiation.The radiation dose (dose) varies depending on the thickness of thecoated layer. The radiation dose is, for example, about 1 to 200 kGy(kilogray), preferably about 5 to 150 kGy, and more preferably about 10to 100 kGy (particularly about 20 to 80 kGy). The acceleration voltageis, for example, about 10 to 1000 kV, preferably about 50 to 500 kV, andmore preferably about 100 to 300 kV.

The irradiation with the active energy ray (in particular, the electronbeam) may optionally be conducted in an atmosphere of an inactive gas(for example, nitrogen gas, argon gas, and helium gas).

As the succeeding step after the curing step by the active energy ray,an aging step may be provided in which the cured hardcoat layer isheat-treated (annealed). In the aging step, the heating temperature is,for example, about 30 to 200° C., preferably about 50 to 190° C., andmore preferably about 60 to 180° C. The heating time is, for example,about 10 minutes to 10 hours, preferably about 30 minutes to 5 hours,and more preferably 45 minutes to 3 hours. In particular, in a casewhere a hardcoat layer having a pencil hardness equivalent to that of aglass is prepared, it is preferred that the heating temperature be alower temperature, for example, about 30 to 150° C., preferably about 50to 120° C., more preferably about 60 to 100° C. (particularly about 65to 90° C.) and the heating time be a longer time, for example, about 0.5to 5 hours, preferably about 1 to 3 hours, and more preferably about 1.5to 2.5 hours.

Meanwhile, in a case where the curable resin composition is thermallycured using a thermal cationic polymerization initiator, the heatingtemperature is, for example, about 30 to 200° C., preferably about 50 to190° C., and more preferably about 60 to 180° C.

As the curing step, a curing step by the active energy ray (such as anultraviolet ray) is preferred in view of applicability to varioussupports.

In particular, since the curable composition of the present inventionand the cured product thereof each have an excellent flexibility, thecombination use of the curable composition or cured product and asupport having an excellent flexibility (such as a soft transparentsubstrate layer) allows the production of the shaped product by aroll-to-roll system. For example, the method of the roll-to-roll systemmay continuously conduct the following steps: a step of paying out arolled support; a step of applying a curable composition on at least oneside of the paid-out support, optionally removing a solvent by drying,and then curing the curable composition; and winding the resultinghardcoat film onto a roller.

The hardcoat sheet composed of the hardcoat layer alone can be obtainedthrough a step of releasing a releasable support from the hardcoatlayer.

EXAMPLES

The following examples are intended to describe this invention infurther detail and should by no means be interpreted as defining thescope of the invention. Raw materials used for Examples and ComparativeExamples are as follows. The hardcoat layers obtained in Examples andComparative Examples were evaluated for the following items.

[Abbreviated Name of Raw Material]

(Curable Resin)

DPHA: dipentaerythritol hexaacrylate, “DPHA” manufactured byDaicel-Allnex Ltd.

IRR214K: tricyclodecanedimethanol diacrylate, “IRR214K” manufactured byDaicel-Allnex Ltd.

TA-100: acrylic silicone resin, “SQ TA-100” manufactured by ToagoseiCo., Ltd.

SI-20: acrylic silicone resin, “SQ SI-20” manufactured by Toagosei Co.,Ltd.

(Leveling Agent)

SILCLEAN3720: hydroxyl group-containing polyether-modifiedpolydimethylsiloxane, “BYK SILCLEAN3720” manufactured by BYK Japan KK

SILCLEAN3700: hydroxyl group-containing silicone-modified acrylic resin,“BYK SILCLEAN3700” manufactured by BYK Japan KK

BYK370: polyester-modified hydroxyl group-containingpolydimethylsiloxane, “BYK370” manufactured by BYK Japan KK

OPTOOL DSX: fluorine compound having hydrolytically condensable group,“OPTOOL DSX” manufactured by Daikin Industries, Ltd.

SURFLON S-242: ethylene oxide adduct of fluorine compound, “SURFLONS-242” manufactured by AGC Seimi Chemical Co., Ltd.

SURFLON S-243: ethylene oxide adduct of fluorine compound, “SURFLONS-243” manufactured by AGC Seimi Chemical Co., Ltd.

SURFLON S-386: polymer of fluorine compound, “SURFLON S-386”manufactured by AGC Seimi Chemical Co., Ltd.

SURFLON S-651: polymer of fluorine compound, “SURFLON S-651”manufactured by AGC Seimi Chemical Co., Ltd.

(Polymerization Initiator)

CPI300PG: photoacid generator, a solution of triarylsulfoniumfluoroalkylfluorophosphate in propylene glycol methyl ether acetate,“CPI300PG” manufactured by San-Apro Ltd.

SAN-AID SI-60S: thermal acid generator, arylsulfonium salt, “SAN-AIDSI-60S” manufactured by Sanshin Chemical Industry Co., Ltd.

IRGACURE 184: photopolymerization initiator, “IRGACURE 184” manufacturedby BASF Japan Ltd.

(Substrate)

PET film: poly(ethylene terephthalate) film having a hardcoat layer on aback side thereof, “0321E188 (WE98-)” manufactured by MitsubishiPlastics, Inc.

[Heat Resistance (5% Weight Loss Temperature (T_(d5)))]

A hardcoat film was obtained in the same manner as in Examples exceptthat a glass plate was used in place of a PET film. From the hardcoatfilm, about 5 mg of a hardcoat layer was cut with a cutter to give asample. The sample was examined for the 5% weight loss temperature usinga differential thermogravimetric analyzer (“TG/DTA6300” manufactured bySeiko Instruments Inc.) under the following conditions.

Measuring temperature range: 25 to 550° C.

Heating rate: 10° C./minute

Gas atmosphere: nitrogen

[Haze and Total Light Transmittance]

The haze and the total light transmittance were measured using a hazemeter (trade name “NDH-5000W” manufactured by Nippon Denshoku IndustriesCo., Ltd.).

[Pencil Hardness]

The pencil hardness of the surface of the hardcoat layer obtained wasmeasured under a load of 750 g in accordance with JIS K5600-5-4.

[Abrasion Resistance]

Using a durability tester provided with a stick 1.0 cm in diametercovered with a #0000 steel wool, the steel wool was allowed to go backand forth on the surface of the hardcoat layer 100 times (at velocity:10 cm/s) under a load of 1.3 kgf/cm². Then the hardcoat film was pastedon a black acrylic plate with an optical agglutinant. The state of thesurface was observed by a fluorescent tube provided with a three-bandfluorescent lamp, and the number of scratches was counted.

[External Appearance]

The external appearance of the hardcoat film obtained was visuallyobserved and evaluated on the basis of the following criteria.

A: The surface is smooth and highly lustrous.

B: The surface has a somewhat uneven thickness.

C: The surface has a significantly uneven thickness and is poorlylustrous.

Reference Example 1 Preparation of Cationic Curable Silicone Resin

In a 300-mL flask (reactor) equipped with a thermometer, a stirrer, areflux condenser, and a nitrogen-introducing tube, 161.5 mmol (39.79 g)of 2-(3,4-epoxy)cyclohexylethyltrimethoxysialne, 9 mmol (1.69 g) ofphenyltrimethoxysilane, and 165.9 g of acetone were put under a nitrogenflow and heated to 50° C. To the resulting mixture, 4.70 g of a 5% byweight aqueous solution of potassium carbonate (potassium carbonate: 1.7mmol) was added dropwise over 5 minutes, and then 1700 mmol (30.60 g) ofwater was added dropwise thereto over 20 minutes. During the dropping, amarked increase in temperature did not occur. Thereafter, thepolycondensation reaction was carried out for 4 hours under a nitrogenflow at a temperature of 50° C.

The analysis of the product in the reaction solution after thepolycondensation reaction showed that the product had a number averagemolecular weight of 1911 and a degree of molecular weight dispersion(molecular weight distribution Mw/Mn) of 1.47. The ratio [the T3unit/the T2 unit] of the T3 unit relative to the T2 unit in the productobtained was calculated by ²⁹ Si-NMR spectrometry and was determined tobe 10.3.

Thereafter, the reaction solution was cooled, and washed with wateruntil the lower layer solution was neutralized. The upper layer solutionwas separated and then distilled out the solvent under the conditions of1 mmHg and 40° C. to give a colorless and transparent liquid product (acationic curable silicone resin containing a silsesquioxane unit havingan epoxy group). The product (ESQ) had a T_(d5) of 370° C.

(Production of Hardcoat Film)

A mixture of 100 parts by weight of the cationic curable silicone resin(ESQ) obtained and 1 part by weight of a photoacid generator (CPI300PG)was prepared and used as a hardcoat liquid (curable composition).

The hardcoat liquid obtained was cast-coated on a PET film with the useof a wire bar #30 and then allowed to stand for one minute in an oven at70° C. (prebaking). Then, the coated film was irradiated with anultraviolet ray at a radiation dose of 400 mJ/cm² for 5 seconds with ahigh-pressure mercury lamp (manufactured by Eyegraphics Co., Ltd.).Finally, the coating of the hardcoat liquid was cured by heat-treating(aging) the film at 150° C. for one hour to give a hardcoat film havinga hardcoat layer. The hardcoat layer had a thickness of 38 μm.

Reference Example 2

A hardcoat film was produced in the same manner as in Reference Example1 except that the cast-coated hardcoat liquid was prebaked for 10minutes in an oven at 70° C. and heat-treated (aged) at 80° C. for 2hours. The hardcoat layer had a thickness of 36 μm.

Examples 1 to 4

As shown in Table 1, a hardcoat film was produced in the same manner asin Reference Example 2 except that a leveling agent, as a raw material,was further added for the preparation of the cationic curable siliconeresin.

Examples 5 to 11

As shown in Table 1, a hardcoat film was produced in the same manner asin Reference Example 1 except that a leveling agent, as a raw material,was further added for the preparation of the cationic curable siliconeresin.

Example 12

A mixture of 100 parts by weight of the curable silicone resin (ESQ)obtained in Reference Example 1, 0.3 parts by weight of a thermal acidgenerator (SAN-AID SI-60S), and 0.5 parts by weight of a leveling agent(SURFLON S-243) was prepared and used as a hardcoat liquid.

The hardcoat liquid obtained was cast-coated on a PET film with the useof a wire bar #30 and then allowed to stand for one minute in an oven at70° C. (prebaking). Then, the coating of the hardcoat liquid was curedby heat-treating the film at 150° C. for one hour to give a hardcoatfilm having a hardcoat layer. The hardcoat layer had a thickness of 36μm.

Comparative Examples 1 to 4

As shown in Table 1, a hardcoat film was produced in the same manner asin Reference Example 1 except that a curable resin and a polymerizationinitiator were mixed to prepare a hardcoat liquid.

The evaluation of the hardcoat films obtained in Examples, ReferenceExamples, and Comparative Examples are shown in Table 1.

TABLE 1 Reference Examples Examples 1 2 1 2 3 4 5 6 7 8 CompositionCurable ESQ 100 100 100 100 100 100 100 100 100 100 (parts by weight)resin PETIA — — — — — — — — — — IRR214K — — — — — — — — — — TA-100 — — —— — — — — — — SI-20 — — — — — — — — — — Leveling SILCLEAN3720 — — — — —— 1 — — — agent SILCLEAN3700 — — 1 — — — — 1 — — BYK300 — — — — — — — —1 — OPTOOL DSX — — — — — — — — — 0.5 SURFLON S-242 — — — — — — — — — —SURFLON S-243 — — — 0.5 — — — — — — SURFLON S-386 — — — — 0.5 — — — — —SURFLON S-651 — — — — — 0.5 — — — — Initiator CPI-300PG 1 1 1 1 1 1 1 11 1 SAN-AID SI-60S — — — — — — — — — — IRGACURE 184 — — — — — — — — — —Thickness (μm) 38 36 34 33 30 35 35 37 35 38 Haze (%) 0.5 0.5 0.5 0.40.2 0.2 0.5 0.6 0.4 0.3 Total light transmittance (%) 91.3 91 91 91 91.191.1 91.2 91.1 91.2 91 Pencil hardness 4H 9H 8H 8H 9H 8H 5H 5H 5H 5HAbrasion resistance about about 0 0 0 0 0 0 0 0 (Number of scratches) 1010 External appearance B B A A A A A A A A Examples Comparative Examples9 10 11 12 1 2 3 4 Composition Curable ESQ 100 100 100 100 — — — —(parts by weight) resin PETIA — — — — 100 — — — IRR214K — — — — — 100 —— TA-100 — — — — — — 100 — SI-20 — — — — — — — 100 Leveling SILCLEAN3720— — — — — — — — agent SILCLEAN3700 — — — — — — — — BYK300 — — — — — — —— OPTOOL DSX — — — — — — — — SURFLON S-242 0.5 — — — — — — — SURFLONS-243 — 0.5 — 0.5 — — — — SURFLON S-386 — — 0.5 — — — — — SURFLON S-651— — — — — — — — Initiator CPI-300PG 1 1 1 — — — 3 3 SAN-AID SI-60S — — —0.3 — — — — IRGACURE 184 — — — — 5 5 — — Thickness (μm) 36 34 35 36 3532 40 37 Haze (%) 0.5 0.3 0.3 0.5 0.4 0.4 1.2 0.8 Total lighttransmittance (%) 91.1 91 91.2 90.8 90 90.2 90.5 91.5 Pencil hardness 5H5H 5H 5H 3H H 2H 2H Abrasion resistance 0 0 0 0 large large large large(Number of scratches) number number number number External appearance AA A B C C C C

As apparent from the results shown in Table 1, the hardcoat filmsobtained in Examples were excellent transparency, hardness, abrasionresistance, and external appearance. In contrast, the hardcoat filmsobtained in Comparative Examples had small hardness and low abrasionresistance and external appearance.

INDUSTRIAL APPLICABILITY

The cured hardcoat layer of the curable composition of the presentinvention is utilizable as a hardcoat layer for coating various bases(or shaped articles) (two-dimensional or three-dimensional bases (orshaped articles)) that require properties including abrasion resistance,heat resistance, surface smoothness, and antifouling property. The curedhardcoat layer, which has an excellent optical properties includingtransparency, is also utilizable for a display unit of various opticaldisplays [for example, electric or electronic equipment or precisionequipment (e.g., a personal computer, a television, a portable telephone(e.g., a smart phone), a tablet computer, a game machine, a mobiledevice, a clock or a watch, and an electronic calculator)], anautomobile windshield, and a window of a building.

1. A curable composition comprising a cationic curable silicone resinand a leveling agent, wherein the cationic curable silicone resincomprises a silsesquioxane unit, has a monomer unit having an epoxygroup in a proportion of not less than 50% by mol in a total monomerunit, and has a number average molecular weight of 1000 to
 3000. 2. Acurable composition according to claim 1, wherein the cationic curablesilicone resin has a silsesquioxane unit represented by the formula (1):R¹SiO_(3/2) wherein R¹ represents a group comprising an epoxy group; ahydrogen atom; or a hydrocarbon group; in a proportion of not less than50% by mol in the total monomer unit constituting the cationic curablesilicone resin.
 3. A curable composition according to claim 1, whereinthe cationic curable silicone resin further comprises a unit representedby the formula (2): R¹SiO(OR²) wherein R¹ represents a group comprisingan epoxy group; a hydrogen atom; or a hydrocarbon group; and R²represents a hydrogen atom or a C₁₋₄alkyl group; and has a molar ratioof the silsesquioxane unit relative to the unit represented by theformula (2) of not less than
 5. 4. A curable composition according toclaim 1, wherein the silsesquioxane unit comprises a unit represented bythe formula (3): R³SiO_(3/2) wherein R³ represents a group comprising analicyclic epoxy group, and a unit represented by the formula (4):R⁴SiO_(3/2) wherein R⁴ represents an aryl group which may have asubstituent.
 5. A curable composition according to claim 1, wherein thecationic curable silicone resin has a molecular weight distributionMw/Mn of 1 to
 3. 6. A curable composition according to claim 1, whereinthe leveling agent comprises at least one of a silicone-series levelingagent and a fluorine-containing leveling agent, and the leveling agenthas at least one of a reactive group to an epoxy group, and ahydrolytically condensable group.
 7. A curable composition according toclaim 1, wherein the leveling agent has a proportion of 0.1 to 10 partsby weight relative to 100 parts by weight of the cationic curablesilicone resin.
 8. A curable composition according to claim 1, whereinthe leveling agent comprises a silicone-series leveling agent having ahydroxyl group, and the leveling agent has a proportion of 0.5 to 5parts by weight relative to 100 parts by weight of the cationic curablesilicone resin.
 9. A shaped product comprising a hardcoat layer, whereinthe hardcoat layer is a cured product of a curable composition recitedin claim
 1. 10. A shaped product according to claim 9, which comprisesthe hardcoat layer alone and has an average thickness of 10 to 200 μm.11. A shaped product according to claim 9, which further comprises atransparent substrate layer, wherein the transparent layer has a sideprovided with the hardcoat layer.
 12. A shaped product according toclaim 10, which is produced by a roll-to-roll system.
 13. A shapedproduct according to claim 9, which comprises the hardcoat layer and athree-dimensional base.